added students to course

app/Controllers/Http/CoursesController.ts

@@ -2,7 +2,9 @@ import { Exception } from '@adonisjs/core/build/standalone';
 import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext';
 import Course from 'App/Models/Course';
 import User from 'App/Models/User';
+import AddCourseToUserValidator from 'App/Validators/AddCourseToUserValidator';
 import CreateCourseValidator from 'App/Validators/CreateCourseValidator';
+import DelCourseFromUserValidator from 'App/Validators/DelCourseFromUserValidator';
 import UpdateCourseValidator from 'App/Validators/UpdateCourseValidator';
 
 export default class CoursesController {
@@ -95,8 +97,16 @@ export default class CoursesController {
 
   /**
    * Show Students of Course with "id"
+   * GET /courses/:id/students
    */
-  public async showStudents({ response, params }: HttpContextContract) {}
+  public async showStudents({ response, params }: HttpContextContract) {
+    const course = await this.Course.query().preload('students').where('id', params.id).firstOrFail();
+
+    return response.ok({
+      message: `Fetched students from course with id: "${course.id}"`,
+      data: course.students,
+    });
+  }
 
   /**
    * Create new Course in a system
@@ -178,4 +188,58 @@ export default class CoursesController {
       data: course,
     });
   }
+
+  /**
+   * Attach student to course
+   * POST /courses/:id/attach-student
+   */
+  async attachStudent({ response, request, params }: HttpContextContract) {
+    try {
+      const payload = await request.validate(AddCourseToUserValidator);
+      const student = await this.User.findOrFail(payload.student_id);
+      const course = await this.Course.findOrFail(params.id);
+
+      await course.load('students');
+      await student.load('roles');
+
+      const studentRoles = student.roles.map(r => r.slug);
+
+      if (!studentRoles.includes('student')) {
+        throw new Exception(`User cannot be attached to the course without "student" role.`, 400, 'E_USER_ROLE');
+      }
+
+      await course.related('students').attach([student.id]);
+
+      return response.ok({
+        message: 'Student attached',
+        data: 'SUCCESS',
+      });
+    } catch (error) {
+      if (error?.code === '23505')
+        throw new Exception('Student already attached to that course', 400, 'E_STUDENT_ATTACHED');
+
+      throw error;
+    }
+  }
+
+  /**
+   * Detach student from course
+   */
+  async detachStudent({ response, request, params }: HttpContextContract) {
+    const payload = await request.validate(DelCourseFromUserValidator);
+    const course = await this.Course.query().preload('students').where('id', params.id).firstOrFail();
+    const candidate = course.students.find(student => student.id === payload.student_id);
+
+    if (!candidate) {
+      throw new Exception('Student not attached to that course', 400, 'E_STUDENT_NOT_ATTACHED');
+    }
+
+    const student = await this.User.findOrFail(payload.student_id);
+    await course.related('students').detach([student.id]);
+
+    return response.ok({
+      message: 'Student detached',
+      data: 'SUCCESS',
+    });
+  }
 }

app/Controllers/Http/UsersController.ts

@@ -122,7 +122,7 @@ export default class UsersController {
 
   /**
    * Attach array of roles to user
-   * POST /users/:id/attach_roles
+   * POST /users/:id/attach-roles
    */
   public async attachRoles({ request, response, params }: HttpContextContract) {
     await request.validate(AddRoleToUserValidator);
@@ -141,7 +141,7 @@ export default class UsersController {
 
   /**
    * Detach array of roles from user
-   * DELETE /users/:id/detach_roles
+   * DELETE /users/:id/detach-roles
    */
   public async detachRoles({ request, response, params }: HttpContextContract) {
     await request.validate(DelRoleFromUserValidator);

app/Models/Course.ts

@@ -1,10 +1,20 @@
 /* eslint-disable no-param-reassign */
 import { nanoid } from 'nanoid';
 import { DateTime } from 'luxon';
-import { BaseModel, beforeCreate, BelongsTo, belongsTo, column, HasMany, hasMany } from '@ioc:Adonis/Lucid/Orm';
-import Category from './Category';
-import Lesson from './Lesson';
-import User from './User';
+import {
+  BaseModel,
+  beforeCreate,
+  BelongsTo,
+  belongsTo,
+  column,
+  HasMany,
+  hasMany,
+  ManyToMany,
+  manyToMany,
+} from '@ioc:Adonis/Lucid/Orm';
+import Category from 'App/Models/Category';
+import Lesson from 'App/Models/Lesson';
+import User from 'App/Models/User';
 // eslint-disable-next-line import/no-cycle
 
 export default class Course extends BaseModel {
@@ -38,6 +48,11 @@ export default class Course extends BaseModel {
   })
   public lessons: HasMany<typeof Lesson>;
 
+  @manyToMany(() => User, {
+    pivotTable: 'users_courses',
+  })
+  public students: ManyToMany<typeof User>;
+
   @column.dateTime({ autoCreate: true })
   public createdAt: DateTime;
 

app/Models/User.ts

@@ -16,6 +16,7 @@ import Hash from '@ioc:Adonis/Core/Hash';
 import { nanoid } from 'nanoid';
 import Role from 'App/Models/Role';
 import Contact from 'App/Models/Contact';
+import Course from 'App/Models/Course';
 
 export default class User extends BaseModel {
   @column({ isPrimary: true })
@@ -43,6 +44,11 @@ export default class User extends BaseModel {
   })
   public roles: ManyToMany<typeof Role>;
 
+  @manyToMany(() => Course, {
+    pivotTable: 'users_courses',
+  })
+  public courses: ManyToMany<typeof Course>;
+
   @column.dateTime({ autoCreate: true, serializeAs: null })
   public createdAt: DateTime;
 

app/Validators/AddCourseToUserValidator.ts

@@ -0,0 +1,12 @@
+import { schema, rules } from '@ioc:Adonis/Core/Validator';
+import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext';
+
+export default class AddCourseToUserValidator {
+  constructor(protected ctx: HttpContextContract) {}
+
+  public schema = schema.create({
+    student_id: schema.string({}, [rules.exists({ table: 'users', column: 'id' })]),
+  });
+
+  public messages = {};
+}

app/Validators/DelCourseFromUserValidator.ts

@@ -0,0 +1,12 @@
+import { schema, rules } from '@ioc:Adonis/Core/Validator';
+import { HttpContextContract } from '@ioc:Adonis/Core/HttpContext';
+
+export default class DelCourseFromUserValidator {
+  constructor(protected ctx: HttpContextContract) {}
+
+  public schema = schema.create({
+    student_id: schema.string({}, [rules.exists({ table: 'users', column: 'id' })]),
+  });
+
+  public messages = {};
+}

database/migrations/1627750162275_users_courses.ts

@@ -0,0 +1,18 @@
+import BaseSchema from '@ioc:Adonis/Lucid/Schema';
+
+export default class UsersCourses extends BaseSchema {
+  protected tableName = 'users_courses';
+
+  public async up() {
+    this.schema.createTable(this.tableName, table => {
+      table.increments('id');
+      table.string('user_id', 21).unsigned().references('users.id').onDelete('CASCADE');
+      table.string('course_id', 21).unsigned().references('courses.id').onDelete('CASCADE');
+      table.unique(['user_id', 'course_id']);
+    });
+  }
+
+  public async down() {
+    this.schema.dropTable(this.tableName);
+  }
+}

start/routes.ts

@@ -72,9 +72,17 @@ Route.group(() => {
       .middleware('role:admin,teacher,student')
       .as('showCourseLessons');
 
-    Route.get('courses/:id/students', 'CourseController.showStudents')
+    Route.get('courses/:id/students', 'CoursesController.showStudents')
       .middleware('role:admin,teacher,student')
       .as('showCourseStudents');
+
+    Route.post('courses/:id/attach-student', 'CoursesController.attachStudent')
+      .middleware('role:admin,teacher')
+      .as('attachUserCourse');
+
+    Route.delete('courses/:id/detach-student', 'CoursesController.detachStudent')
+      .middleware('role:admin,teacher')
+      .as('detachUserCourse');
   }).middleware('auth');
 })
   .prefix('/api/v1')